1. Field of the Invention
This invention relates to boots which are intended to fit over the electrical connection between a spark plug and a spark plug cable. More particularly, this invention relates to an angled boot which is intended to fit over an angled spark plug cable terminal.
2. Description of the Prior Art
Elastomer boots are used to cover the connection between a spark plug and its associated spark plug cable. These boots serve as a dielectric and a moisture shield for the high voltages carried through the connection. In most applications, the spark plug cable terminal is structured to attach to the spark plug electrode in a direction coinciding with the axial attitude of the spark plug. Thus, in these common situations, the boot need only be structured to accommodate a 180.degree. orientation between the spark plug and the spark plug cable terminal.
Modern gasoline engines are frequently situated in cramped engine compartments, resulting in a need to provide terminals having other than 180.degree. configurations. Those situations utilizing 90.degree. configurations in the spark plug cable terminal are covered by an elastomer boot of a similar shape. These 90.degree. boots permit easy and assured installation of the spark plug cable terminal onto the spark plug electrode because the mechanic need only press down on the horizontal component on the boot to ensure proper seating of the spark plug cable terminal.
Situations involving other than 180.degree. and 90.degree. spark plug cable terminal configurations make the connection to the spark plug frequently very difficult. This is because the angle of the spark plug cable terminal is such as to preclude the mechanic from having any point on the boot surface which is above the connection point with the spark plug electrode. Accordingly, he can't press the boot directly downward onto the spark plug. Secondly, because these situations are frequently accommodated by the use of 180.degree. boots, a poor and loose fit results which yields very poor dielectric and moisture barrier characteristics.
Several attempts have been made in the prior art to develop a boot for applications involving angles of the spark cable terminal at other than 180.degree. or 90.degree..
U.S. Pat. No. 2,792,558 to Woofter is directed to solving the problem of assembling a boot over an acutely angled spark plug cable terminal. He solves this problem by providing a boot having an acute angle within which is a terminal having a head and circular portion angled to accept the spark plug when inserted into the boot.
U.S. Pat. No. 3,354,419 to Miller, Jr. is directed to the problem that prior art boots accommodate only 90.degree. and 180.degree. spark plug cable terminals. He solves this problem by providing a variable angle spark plug cable terminal and a two (2) component boot which is held together by a screw.
U.S. Pat. No. 3,867,001 to Hedman is directed to the problem of degradation of the spark plug coupling because of proximity to the exhaust manifold. He solves this problem by providing an adapter to move the spark plug cable connection to a laterally displaced location. The insulator boot has an angle other than 180.degree. or 90.degree..
U.S. Pat. No. 4,413,870 to Labutski, III is directed to solving the problem that a spark plug cable of an engine must be individually sized and angled for each particular spark plug. He solves this problem by providing a position retaining mechanism between two wire clamps and covering these with a flexible boot having serrations to facilitate flexing.
None of the above cited patents solve the problem of providing a custom boot for spark plug cable terminals having an angle other than 180.degree. or 90.degree., which further provides a structure that ensures proper seating of the spark plug during installation on a spark plug. Additionally, none of the cited patents has adequately addressed the problem of insulator slippage along the boot which can give a mechanic a false sensation of a properly seated spark plug cable terminal. Lastly, the above cited patents do not address the important issue of reasonable cost and high reliability.
Hence, there remains a problem in the art to devise a spark plug boot which specifically accommodates spark plug cable terminals having angles other than 180.degree. or 90.degree., which has provision to assure seating of the spark plug cable terminal onto the spark plug electrode, as well as prevention of insulator slippage within the boot and, finally, which is inexpensive and very reliable.